Magnetic prosthetic

ABSTRACT

The present invention is directed generally to (1) an articulating junction, and articulation method thereof, wherein articulation is facilitated by a plurality of magnetic particles; (2) an articulating junction, and articulation method thereof, wherein the stability and fluidity of the junction is based, at least in part, on the magnetic field(s) of the plurality of magnetic particles; and (3) reducing the resistance to articulation and/or increasing the structural integrity and support, of the articulating junction, via electro-magnetism. Further, the present invention is directed generally to the synergistic combination of magnetic particles and preferred bio-implant-materials and additive-manufacturing methods along with Baker correlation codes. Further, the present invention is directed to an artificial joint for implantation into a living body and methods for constructing such an artificial joint.

BACKGROUND OF THE INVENTION Technical Field

The present invention is generally directed to an articulating junction,and articulation method thereof, wherein articulation is facilitated bya plurality of embedded magnetic granules/grains and, in one exemplaryembodiment, a polymer bonded magnetic system(s). The present inventionalso is generally directed to an articulating junction, and articulationmethod thereof, wherein the stability and fluidity of the junction isbased, at least in part, on the specific stray magnetic field(s), andthe corresponding magnetization profile and structure-in-volume/bulkgeometric shape, of the embedded magnetic profile. Further, the presentinvention is directed generally to: (1) reducing the resistance toarticulation, and/or (2) increasing the structural integrity andsupport, of the articulating junction, via predefined stray magneticfield(s) (e.g., non-mechanical forces acting on at least a portion ofthe articulating junction based at least in part on a predefinedvariable magnetic pattern, shape, and/or fraction in the articulatingjunction).

Further, the present invention is generally directed to the synergisticcombination of embedding magnetic patterns, shapes, and/or bulkgeometric structures, via software-controlled magnetization processes,with preferred bio-implant-materials and additive-manufacturing methods.In this way, the present invention also is generally directed tomethods, and therapeutic devices/implants/prosthetics, and methods ofmanufacture thereof, for the prevention and treatment of variousconditions (e.g., amputations, replacements, augmentations, andsecondary conditions like inflammation, auto-immune rejection,osteolysis).

Further, the present invention is directed to an artificial joint forimplantation into a living body and methods for constructing such anartificial joint. In some embodiments, a magnetic prosthetic solution,that overcomes the above shortcomings in the prior art, leveragesnano-magnetic structures or programmable magnets for in situ, in vivouse (e.g., under biological conditions and immunoactivity) that providesa smooth translation of the joint through its range of motion.

Prior Art

The stability and structural integrity of an articulating junction, inthe field of biomechanics for example, is a compromise betweenbiomechanics of design and integrity of existing biological structures.

Orthopedics is a medical subspecialty that treats disorders of the humanbody related to bones, muscles, ligaments, tendons, and joints, with itscurrent emphasis on the treatment of the bones and joints. The treatmentof bone and joint disorders can be generally sub classified intocategories including the treatment of bone fractures, joint instability,early stage arthritis, and end stage arthritis. Originally, thetreatment of orthopedic conditions mainly relied on casting and bracing.With the advent of new implantable materials, however, and developmentof better joint replacement prostheses, orthopedics shifted its focus tobecome increasingly more of a surgical subspecialty. With improvedmaterials, better engineering, and a better understanding of the humanbody, the practice of orthopedic medicine and biomechanicalexperimentation have made remarkable progress. The treatment of bonefractures and joint disorders has continually been refined to thepresent state of the art.

Prior art innovations have concentrated on developing static mechanicaldesign characteristics and new implantable materials used for fracturetreatment in total joint arthroplasties. These static mechanical designcharacteristics have been directed to solutions for problems concerningwear, stability, and methods of fixation for the total jointarthroplasties. They have also been utilized to improve the currentstate of the art concerning fracture treatment.

Arthroplasty is a surgical procedure used to restore the function of ajoint by resurfacing the bone with a prosthetic joint. In the case ofboth knee and hip arthroplasty, this procedure can help relieve pain andrestore function in a severely diseased joint. This treatment optioninvolves cutting away damaged bone and cartilage and replacing it withan artificial joint made of either metal alloys, high-grade plastics orpolymers. This type of treatment procedure known in the art producesreliable symptomatic relief but are prone to instability and prematurewear, especially in younger more active patients. Physiological impacts,such as tissue inflammation surrounding the prosthesis, often are thecause of premature artificial joint failure (described in greater detailbelow).

As a result, revision surgery for joint replacement failure may benecessary due to the corrosion or wear on the implant surfaces.Additionally, in terms of hip joint failure the most common problem isdislocation due to the fact that the man-made hip is smaller than theoriginal joint, this causes the ball to come out of its socket.

More specifically, hip and knee joint replacements are the most commonlyperformed joint replacement surgical procedures in which parts of anarthritic or damaged joint is removed and replaced with a metal, plasticor ceramic device termed joint implants. Joint implants or what commonlycan be referred as prosthetic joints, are long-term implantable surgicaldevices that are used to either completely or partially replace thestructural elements within the musculoskeletal system to improve andenhance the function of the joint.

The basic anatomy of a joint is where the ends of two or more bonesmeet. Specifically, the knee joint is one of the largest and mostcomplex joints in the body. The knee, also known as the tibiofemoraljoint, is a synovial hinge joint formed between three bones: the femur,tibia, and patella. Further, the joint-forming surfaces of each bone arecovered in a thin layer of hyaline cartilage that gives them anextremely smooth surface and protects the underlying bone from damage.Between the femur and tibia is a figure-eight-shaped layer of tough,rubbery fibrocartilage known as the meniscus. The meniscus acts as ashock absorber inside the knee to prevent the collision of the leg bonesduring strenuous activities such as running and jumping.

As mentioned, the knee is a type of synovial joint, as with all synovialjoints, a joint capsule surrounds the bones of the knee to providestrength and lubrication. This capsule is composed of fibrous connectivetissue continuous with the ligaments of the knee to hold the joint inproper alignment. Further, the anterior, posterior and medial surfacesof the knee are all held in place by various ligaments and thesestructures along with the joint capsule help support the knee bymaintaining its ability to permit the flexion and extension of the lowerleg relative to the thigh.

Physiology changes to the above mentioned joint structures are thoughtto contribute towards the progression of a diseased knee joint leadingto the consideration of joint replacement surgery. Some of these changesincludes: measurable differences in overall knee cartilage volume andtibial cartilage volume, measurable differences in bone size, meniscaltears and bone marrow lesions.

The hip joint is also a type of synovial joint, specifically termed aball- and socket synovial joint. The ball is the femoral head and thesocket is the acetabulum. The femur is the longest and heaviest bone inthe human body and consist of a superior/proximal end, a shaft, and aninferior/distal end. It is the superior end of the bone connecting tothe side of the acetabulum. The superior end of the femur consists of ahead and a neck, to which the head of the femur is angled superomediallyand slightly anteriorly when connecting with the acetabulum. The head isattached to the femoral body (shaft) by the neck of the femur.

The hip joint is the articulation of the pelvis with the femur, whichconnects the axial skeleton with the lower extremity. The hipbone isformed by the fusion of the ilium, the ischium, and pubis. The ilium isthe largest part of the hip bone and makes up the superior part of theacetabulum. The ischium is the inferior aspect of the pelvis, thesuperior part of the ischium fuses with the pubis and ilium, forming theposteroinferior aspect of the acetabulum. The pubis, makes up theanteromedial part of the hip bone and contributes to the anterior partof the acetabulum. As noted, the acetabulum is formed from parts of theilium, ischium, and pubis. This a cup-shaped socket component on thelateral aspect of the pelvis which articulates with the head of thefemur to form the hip joint.

The hip joint can be defined as the connection of the proximal side ofthe acetabulum and the distal neck portion of the femur by strongfibrous capsules and ligaments. As in the knee joint, physiology changesto these structures are thought to contribute towards the progression ofdecreased function and pain in the hip joint leading to theconsideration of joint replacement surgery. Some of these changesinclude: measurable differences in overall cartilage volume andmeasurable changes in bone mineral density.

Artificial joint prostheses are used as a surgical therapeuticsubstitute for joint components that are damaged, such as due to injuryor osteoarthritis. The goals of surgical implantation of artificialjoint prostheses generally include improving joint function andalleviating pain. Although these surgeries have a high success rate,there is some risk over time that an artificial joint prosthesis canfail. Failure of artificial prosthetic joints can require furthersurgery, with associated costs and morbidity for the patient. Oneclinically significant type of artificial joint failure is associatedwith loosening of the prosthesis at the bone interface, includingosteolysis and related damage to the bone.

Artificial joint prosthesis failure is associated in a significantnumber of cases with loosening of the prosthesis at the prosthesis jointinterface or in the periprosthetic region due to loss of the adjacentbone. This is believed to be caused in part from osteolysis promoted bythe body's response to debris from the artificial joint prosthesis. Weardebris from the prosthesis surface coming into contact with thebone-prosthesis interface has been implicated, for example, in looseningof the prosthesis and associated failure. Debris particles at theprosthesis-bone interface can contribute to osteolysis and resultingprosthesis loosening with potential failure of the prosthesis.

Debris particles within the synovial fluid can include, for example, oneor more of: cellular debris particles, particulates of bone andprosthesis generated during surgery, and particulates formed from wearof the artificial joint prosthesis. Some studies indicate that debrisparticles can enter the prosthesis-bone interface region throughincreased synovial fluid pressure at the prosthesis joint interfaceduring physiological movement. Some studies indicate that debrisparticles can enter the prosthesis-bone interface region throughincreased synovial fluid flow rate against the prosthesis jointinterface during physiological movement. Studies also indicate that bothfluid pressure and flow rate at the prosthesis-joint interface due toprosthesis movement during physiological activities encourage debrisparticles to enter the prosthesis-bone interface, contributing toosteolysis and prosthesis failure.

To combat such failures in the prior art, prior art solutions haveincorporated discrete conventional standard magnet inserts or plugs atthe juxtaposed surfaces of a prosthesis in an effort to leveragemagnetically repelling forces to reduce friction. Prior art solutionsusing a plurality of discrete and embedded magnets in prosthesis,however, have exhibited undesirable performance characteristics. Forexample, prior art solutions that embeds magnets in a prosthetic jointare prone to corrosion. Additionally, patients using prior art solutionsthat embed magnets in a prosthetic joint tend to experience a “jerky”motion as the various embedded magnets sequentially release from, andsubsequently engage, complementary magnetic fields generated by othernearby embedded conventional standards magnets.

Pursuant to the foregoing, it may be regarded as an object of thepresent invention to overcome the deficiencies of, and provide forimprovements in, the state of the prior art as described above, and asmay be inherent in the same, or as may be known to those skilled in theart. It is a further object of the present invention to provide atherapeutic treatment and method and any necessary apparatus forcarrying out the same, and of the foregoing character, and in accordancewith the above objects, which may be readily carried out, with andwithin the process, and with comparatively simple equipment, and withrelatively simple engineering requirements. Still further objects may berecognized and become apparent upon consideration of the followingspecification, taken as a whole, wherein by way of illustration andexample, an embodiment of the present invention is disclosed.

As used herein, any reference to an object of the present inventionshould be understood to refer to solutions and advantages of the presentinvention, which flow from its conception and reduction to practice, andnot to any a priori or prior art conception.

The above and other objects of the present invention are realized andsome limitations of the prior art are overcome in the present inventionby providing new and improved methods, processes, compositions, andsystems. A better understanding of the principles and details of thepresent invention will be evident from the following description.

BRIEF SUMMARY OF THE INVENTION

An exemplary embodiment of the present invention relates to prostheticcomponents and, in particular, to total joint replacement using embeddedmagnetic granules/grains to control the instability of joint-replacementsurgery.

The exemplary embodiment may comprise embedded magnetic granules/grainsthat may be manipulated, using magnetic fields, to obtain specificallyand purposely designed magnetic system(s). Further, the exemplaryembodiment may comprise magnetic filler particles (for example, softmagnetic alloys or hard magnetic alloys like ferrite as well asrare-earth materials—embedded inside a thermosoftening polymer bindermatrix to form a polymer bonded permanent magnet with the freedom ofhaving a specific complex shape with locally tailored magneticproperties and predefined stray field(s) in a given region. Theprosthetic component also may comprise conductive graphene/PLA compositefilament and/or ceramics or electromagnets.

Further, the exemplary embodiment may comprise locally-differentpolymer-matrix material concentrations, and different types of magneticfiller particles, as well as continuous changes from magnetic materialto non-magnetic material. This provides tailored magnetic propertiesand/or smooth transitions between strong and weak magnetism, offeringapplications requiring custom external field profiles.

The polymer bonded permanent magnet may be isotropic (non-directional)or anisotropic (directional) with high dimensional accuracy. Ifanisotropic, the magnetic system may be produced, at least in part, viaa software controlled magnetization process that locally magnetizes oraligns the magnetic particles during the solidification/formationprocess. This enables precision control over the magnetic field(s).

The exemplary embodiment also may comprise a magnetic structure thatincorporates correlated patterns of magnets with alternating polarity,designed to achieve a desired behavior and deliver strong localizedmagnetic fields. The prosthetic component (or repaired articulationjunction, etc.) comprising the magnetic structure may be configured as amultipole structures made up of multiple magnetic elements (maxels) ofvarying size, location, orientation, and saturation. By accuratelyarranging or overlapping the maxels, for example, and by varying thepolarity and/or field strengths of each source of the arrays of magneticsources that make up the magnetic structure, intricate magnetic fieldsor stray fields are produced, and may be leveraged to control theinstability of joint-replacement surgery.

The exemplary embodiment also may comprise magnetic nano-particles tocontrol the instability of joint-replacement surgery; however, thenano-scale is merely a non-limiting example.

Further, an exemplary embodiment of the present invention provides aprosthetic system that incorporates embedded magnetic granules/grains, amagnetic pattern, shape, and/or bulk geometric structure, ornano-magnetic particles, or programmable magnets, etc. into either thefabrication of the various prosthetic components, or onto the surfacesof the various prosthetic components, or directly into the articulatingjunction to be repaired. The fabrication process of the magnetic systemmay involve encapsulation/surrounding of the magnetic elements orparticles of the magnetic system with a biocompatible shell/buffer suchas silica or graphene.

If primarily magnetic particles, for example, either nano- or microetc., the fabrication process may further be processed by either: (1)Dispersion of the encapsulated magnetic particles in a solution ofeither methyl methacrylate (PMMA), polyethylene(PE), and/or abiocompatible oxide ceramic and allow the magnetized material to hardeninto a solid state to construct the prosthetic with the use of 3Dprinting; (2) Application of the magnetic particle solution such that itis adhered to surfaces of the prosthetic joint (such as via a structuredfilm comprised of layers of liquid or dried powder comprising theencapsulated magnetic nanoparticles); and/or (3) Collection of magneticparticles in a dried powder such that it is manufactured into an alloyfor the creation of an oxygen-diffused outer surface of the jointprosthetic. Spraying a jet of materials and/or magnetic particles ontothe surface/structure being built up may be involved as a method step aswell.

Further, an exemplary embodiment of the present invention provides asolution that leverages the embedded magnetic granules/grains, themagnetic pattern, shape, and/or bulk geometric structure, ornano-magnetic particles, or programmable magnets, etc. to create a lowfriction “cushion” between two surfaces of a prosthetic joint. It isalso envisioned that other embodiments of the solution may leverage theembedded magnetic granules/grains, the magnetic pattern, shape, and/orbulk geometric structure, or nano-magnetic particles, or programmablemagnets, etc. to generate an attractive force between two surfaces in aprosthetic joint, thereby mitigating the probability of jointseparation. It is possible that a spring-like effect may be created andleveraged as well.

Further, an exemplary embodiment of the present invention provides asolution that uses of rare-earth, magnetic-field joint surfaces in theprosthetic components, as opposed to prior art solutions that simplyembed a plurality of conventional standard magnet plugs, and, in doingso, may overcome the prior art shortcomings.

Further, an exemplary embodiment of the present invention provides aprosthetic system comprising a magnetic system configured to yield aspecific pre-determined stray magnetic field of complex form. The strayfield may be configured as a special magnetic field with field linesarranged in a very specific way—such as a magnetic field that remainsrelatively constant along one direction but which varies in strengthalong another direction, as a non-limiting example. In one exemplaryembodiment, in order to achieve such requirements, the magnetic system,if produced via additive manufacturing methods, is produced with asophisticated geometric form.

The magnetic system may be designed via computer software, before orduring, which adjusts the shape until all requirements for the desiredmagnetic profile are met. Once the desired geometric shape, the additivemanufacturing system may use specialty produced filaments of a magneticparticle, which are held together by a polymer binding materialpreferred for prosthetics. The additive manufacturing system may preparethe additive material for application and may apply it point-by-point inthe desired locations using a nozzle or spray or atomizer or particledeflector or accelerator. This results in a customized, made-to-order,on-demand system that is cost- and time-effective, which can becustomized and adjusted before or during manufacture.

Further, an exemplary embodiment of the present invention provides aprosthetic system comprising a magnetic system configured to yield aspecific pre-determined stray magnetic field, but which requires asoftware-controlled magnetization process to adjust the orientationand/or polarity of the magnetic system (before or during manufacture).The software-controlled magnetization process enables precision controlover the magnetic field of the final product. In this way, the magneticsystem may provide improved attraction forces, repulsion forces, and/oralignment, which is impossible with conventional standard magnet plugsor plates. In one exemplary embodiment, the software-controlledmagnetization process applies, at least in part, Barker correlationcodes, from communications theory, to the magnetic system.

For example, the magnetic system may be designed to not only hold whenattached but, unlike a convention magnet, it may be engineered with adistinct and separate force curve to also lightly repel when misalignedor aligned or partially aligned, etc. Further, the magnetic system maylightly repel anywhere along its length/shape/pattern when notaligned/aligned and may precisely align and attract with substantialstrength when oriented appropriately. In the end, the magnetic systemmay operate at least in part as a polymagnetic spring and/orpolymagnetic latch and/or equivalent as is understood in the art. It isenvisioned that the software-controlled magnetization process mayinvolve locally magnetizing, or aligning, magnetic particles ifapplicable during the solidification process to obtain complex internalmagnetization profiles.

Further, an exemplary embodiment of the present invention provides aprosthetic system that incorporates magnetic nano-particles withbiocompatible shells, respectively, comprising alloys of rare-earthelements including: lanthanide, scandium and yttrium. The magneticnano-particle-imbued solution essentially comprises an exchange-couplednano-composite architecture wherein the atoms of rare-earth elementshave high magnetic momentum or torque.

Further, an exemplary embodiment of the present invention provides anexemplary embodiment of a prosthetic joint comprising correlated magnetpairs programmed to attract and/or repel with a prescribed force andengagement distance, or to attract and/or repel at a certain spatialorientation. The correlated magnets may be engineered to interact onlywith other magnetic structures that have been similarly engineered torespond, for example, with others that yield a cog-shaped field. Thecorrelated magnets also may have a resulting magnetic structure that isone-dimensional, two-dimensional, three-dimensional, if produced usingan electromagnetic array; however, multipole magnetic systems may beconstructed from discrete permanent magnets, or by exposing heatedmagnetizable material, for example, to a coded magnetic field.

Further, an exemplary embodiment of the present invention provides anexemplary embodiment of a prosthetic joint comprising at least onecomponent fabricated from at least one polymer and a plurality ofmagnetic particles. The at least one component fabricated from at leastone polymer and a plurality of magnetic particles includes a surfacesubject to wear during physiological use of the joint, which can bedescribed as a contact surface or a weight-bearing surface, for example.

Further, an exemplary embodiment of the present invention relates to amethod of making a magnetized medical implant. The exemplary methodincludes the steps of providing a substrate and depositing a magnetparticle layer onto a surface of the substrate and/or within a new oradditional layer onto a substrate or base.

An exemplary magnetic prosthetic joint comprises at least one componentthat includes at least a first plurality of magnets configured to createa magnetic field within, about, and/or surrounding the joint, themagnetic field directed to influence the articulation and smooth andsturdy translation of the joint through its ranges of motion in vivo.The components of the prosthetic joint, therefore, may be influenced bythe magnetic force while in their mechanical arrangement in vivo.

Embodiments of the nano-magnetic prosthetic according to the solutionare not limited to the exemplary aspects and features described above orbelow. Certain embodiments may include additional features, or differentfeatures, while other embodiments include alternative features.

BRIEF DESCRIPTION OF THE DRAWINGS

In the Figures, like reference numerals refer to like parts throughoutthe various views unless otherwise indicated. For reference numeralswith letter character designations such as “102A” or “102B”, the lettercharacter designations may differentiate two like parts or elementspresent in the same Figure. Letter character designations for referencenumerals may be omitted when it is intended that a reference numeral toencompass all parts having the same reference numeral in all Figures.

FIGS. 1A and 1B collectively illustrate an exemplary embodiment of aprior art basic artificial knee joint structure showing a diseased kneereplaced by an artificial joint made of either metal alloys, high gradeplastics or polymers, in which a plastic spacer in placed between thefemoral and tibial component;

FIGS. 2A and 2B collectively illustrate an exemplary embodiment of aprior art basic artificial hip joint structure showing a diseased hipreplaced by an artificial joint made of either metal alloys, high gradeplastics or polymers, in which a plastic spacer in placed between theacetabular component and femoral head;

FIG. 3 is an illustration of an exemplary embodiment of a magneticnano-particle with a magnetic core and a biocompatible coating;

FIGS. 4A, 4B, 4C and 4D illustrate perspective views of exemplaryembodiments of a detached nano-magnetic knee replacement in accordancewith the solution, including components composed of hardened magneticnano-particles that either partially coat or fully coat the joint;

FIGS. 5A, 5B, 5C and 5D illustrate perspective views of exemplaryembodiments of an attached nano-magnetic prosthesis to its respectiveknee joint in accordance with the solution, including componentscomposed of hardened magnetic nano-particles that either partially coator fully coat the joint;

FIGS. 6A, 6B, 6C and 6D illustrate perspective views of exemplaryembodiments of a detached nano-magnetic hip replacement in accordancewith the solution, including components composed of hardened magneticnano-particles that either partially coat or fully coat the joint;

FIGS. 7A, 7B, 7C and 7D illustrate perspective views of exemplaryembodiments of an attached nano-magnetic prosthesis to its respectivehip joint in accordance with the solution, including components composedof hardened magnetic nano-particles that either partially coat or fullycoat the joint;

FIG. 8 is a side perspective view of an exemplary embodiment of aprosthetic system comprising a magnetic system configured to yield aspecific pre-determined stray magnetic field of complex form;

FIGS. 9A and 9B are perspective views of an exemplary embodiment of aprosthetic system like that of FIG. 8, but to illustrate the repulsiveand attraction force possibly involved in the prosthetic system;

FIG. 10 is a magnified perspective views of an exemplary embodiment of aprosthetic system like that of FIG. 9A, but to illustrate the smoothtransition between strong and weak magnetism;

FIG. 11 is a front perspective view of an exemplary embodiment of aminimized prosthetic system comprising a correlated magnet pair 1100programmed to attract and/or repel with a prescribed force andengagement distance, or to attract and/or repel at a certain spatialorientation; and

FIGS. 12A and 12B illustrate a flow chart of an exemplary embodiment ofa method of manufacturing the magnetic prosthetic of FIGS. 9-10.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

For a further understanding of the nature, function, and objects of thepresent invention, reference should now be made to the followingdetailed description. While detailed descriptions of the preferredembodiments are provided herein, as well as the best mode of carryingout and employing the present invention, it is to be understood that thepresent invention may be embodied in various forms. Therefore, specificdetails disclosed herein are not to be interpreted as limiting, butrather as a basis for the claims and as a representative basis forteaching one skilled in the art to employ the present invention invirtually any appropriately detailed system, structure, or manner.

The present invention is based, at least in part, on the discovery thatthe electro-magnetic fields of embedded magnetic granules/grains,magnetic patterns, shapes, and/or bulk geometric structures, ornano-magnetic particles, or programmable magnets, etc., and theattractive and/or repulsive forces correlated thereto, can be leveragedto improve the structure and operation of an articulating junction.

As context, there have been some prior art attempts to developapplications that utilize nonmechanical forces to augment the treatmentof particular orthopedic problems. For example, a pulsatingelectromagnetic field has been used as an adjunct to stimulate bonehealing. Biochemical and biomaterial means have been used to alter theenvironment at fracture sites and in joints to aid healing and todecelerate disease processes. Others have attempted to utilize magneticfields in treatment of bone and joint disorders as well.

By using a nonmechanical force, such as magnetized implants, tosupplement a joint, various wear problems may be eliminated from thejoint implant. Wear problems are often caused by excessive articulationbetween two elements and often result in additional surgeries to apatient to replace worn implants. Since two elements having a resultantrepulsive magnetized force do not generally abut one another, the wearbetween two such elements is greatly reduced, thereby extending the lifeexpectancy of the implant. There remains a need in the art, however, forimproved devices and methods for restraining bones in treatment oforthopedic conditions using implants with embedded magnetic systems.

For example, conventional magnets are mainly produced by sintering(using heat, pressure, or both, to create a solid from a mass of powder,for example, and then cutting and/or slicing and/or chiseling into therequired shape) or injection molding and hence limited in complexity oftheir shapes. For sintering, manufacturing may result in material wasteof as much as 30% to 50% of the original material as the sinteredproduct is more brittle and prone to corrosion. For injection molding,including magnetic elements into the mold substrate requires particularand limited fluidity requirements. This is due to rising filler contentwhich increases the viscosity of the compound, leading to fillingproblems within the mold cavity. For this reason, the matrix material islimited to being those of high flowability and good mechanicalproperties. In either situation, standard magnets are limited to abasic, conventional field based on the standard north south polarityalignment. Further, the field is not inherently limited in terms offield strength, distance, or interference. In this way, it must be keptin mind throughout this disclosure that you cannot change the shape ofthe force curve on a conventional magnet, nor define how it behaves whenmisaligned/properly aligned. These are all but some of the limitationsof the prior art.

Herein, the unexpected role of embedded magnetic granules/grains,magnetic patterns, shapes, and/or bulk geometric structures, ornano-magnetic particles, or programmable magnets, etc., and derivativesthereof, as an articulating junction improvement, is explored.

At a very high level, an exemplary embodiment of the present inventionrelates to prosthetic components and, in particular, to total jointreplacement using magnetic nano-particles to control the instability ofjoint-replacement surgery. Further, the exemplary embodiment maycomprise magnetic nano-particles that may be manipulated using magneticfields. The physical and chemical properties of these magneticnano-particles may largely depend on their synthesis method and chemicalstructure.

As is understood by a person having ordinary skill in the art, magneticnano-particles may range from 1.0 to 100.0 nm in size. Further,individual nano-particles when clustered together may form nanosphereswhich can be assembled into a material that is agglomerated, highlyconcentrated and deliverable in a solution or as a dried powder suitablefor dispersion in water or other solvent. Specifically, it is envisionedthat magnetic iron oxide nanoparticles that can be produced via thethermal decomposition of organometallic precursors at high temperaturein organic solvent, producing highly monodisperse, organic-solventcompatible nanoparticles, may be transferred into aqueous-compatiblesolvents by modifying the surface of the nanoparticles or growing auniform silica coating around nanoparticles.

Further, the magnetic nano-particles comprised within the exemplaryembodiment may comprise magnetic material including iron, nickel,cobalt, etc.; however, it is envisioned that a magnetic nano-particlematerial may be colloidal iron oxide (Fe₃O₄), which is known to exhibitsuperparamagnetic properties at ambient temperatures and, as such, maybe preferred for biomedical applications. The size, non-toxicity andsuperparamagnetic properties of magnetic nano-particles make thempreferred for fabrication of prosthetic joints, for example.

Further, and with reference to structure and methods of manufacture oruse, an exemplary embodiment of the present invention provides aprosthetic system that incorporates magnetic nano-particles into eitherthe fabrication of the various prosthetic components or onto thesurfaces of the various prosthetic components. The fabrication processmay involve encapsulation of iron-core magnetic nano-particles with abiocompatible shell (to combat corrosion, and immunological responses,and prevent toxic leaching, for example) such as silica or graphene. Thefabrication process may then further be processed by either: (1)Dispersion of the encapsulated magnetic nano-particles in a solution ofeither methyl methacrylate (PMMA), polyethylene(PE), and/or abiocompatible oxide ceramic and allow the magnetized material to hardeninto a solid state to construct the prosthetic with the use of 3Dprinting; (2) Application of the magnetic nano-particle solution suchthat it is adhered to surfaces of the prosthetic joint (such as via anano-structured film comprised of layers of liquid or dried powdercomprising the encapsulated magnetic nanoparticles); and/or (3)Collection of magnetic nano-particles in a dried powder such that it ismanufactured into an alloy for the creation of an oxygen-diffused outersurface of the joint prosthetic.

Further, an exemplary embodiment of the present invention provides asolution that uses encapsulated magnetic nano-particle to create a lowfriction “cushion” between two surfaces of a prosthetic joint (such asin a knee). It is also envisioned that other embodiments of the solutionmay use encapsulated magnetic nano-particles to generate an attractiveforce between two surfaces in a prosthetic joint, thereby mitigating theprobability of joint separation (such as in a shoulder).

Further, an exemplary embodiment of the present invention provides asolution that uses of rare-earth, magnetic-field joint surfaces in theprosthetic components, as opposed to prior art solutions that simplyembed a plurality of standard magnetic plugs, and, in doing so, mayovercome the prior art shortcomings. Benefits of the solution include,but are not limited to, unaltered joint space, no third body wear,decrease in osteolysis, and minimal bone stock loss.

Further, an exemplary embodiment of the present invention provides aprosthetic system that incorporates magnetic nano-particles withbiocompatible shells, respectively, comprising alloys of rare-earthelements including: lanthanide, scandium and yttrium. The magneticnano-particle-imbued solution essentially comprises a exchange-couplednano-composite architecture wherein the atoms of rare-earth elementshave high magnetic momentum or torque. The exchange-couplednanocomposite may be fabricated utilizing nanoparticles as buildingblocks, by exploiting nanoscale effects, and, therefore, facilitates theproduction of permanent magnet/magnetic features. Similarly, thenanocomposites may be composed of soft magnetic alloys or hard magneticalloys like ferrite—e.g., Sr. Ba—as well as rare-earth materials—e.g.,neodymium ion boron [NdFeB] or samarium cobalt [SmCo] or dysprosium thatare ideal for generating a permanent magnet.

Further, an exemplary embodiment of the present invention provides anexemplary embodiment of a prosthetic joint comprising at least onecomponent fabricated from at least one polymer and a plurality ofmagnetic particles. The at least one component fabricated from at leastone polymer and a plurality of magnetic particles includes a surfacesubject to wear during physiological use of the joint, which can bedescribed as a contact surface or a weight-bearing surface, for example.The magnetic particles within the polymer may be dispersed within thepolymer structure or within a layer/portion/frequency of the structureat a density sufficient and satisfactory to known and expected safetystandards in the biomedical field.

Further, an exemplary embodiment of the present invention provides anexemplary embodiment of a prosthetic joint comprising at least onecomponent fabricated from at least one polymer and a plurality ofmagnetic particles, wherein the magnetic particles are derived fromfilament containing 45-65% by volume of magnetic granules. As thefilament is melted, it is extruded by the printer, for example, to builda shape up layer-by-layer. It is envisioned that the magnetic granulesstart out in an unmagnetized state, but placing the printed object intoa strong magnetic field of the required geometry (described in greaterdetail herein) converts them into the desired magnetic profile, whichcan then be retained permanently.

As a non-limiting alternative, the process may start with pelletscontaining a blend of 65% NdFeB and 35% nylon, for example. The NdFeBparticles/granules may be initially demagnetized; each particle havingapproximately zero net magnetization. These components may then bemelted and extruded by a system like the Big Area Additive Manufacturing(BAAM) machine. In another alternative, the process is intended for alower-cost, end-user commercially available 3D printer (such as theBuilder 3D printer from Code P®) with commercially available NdFeBpowder inside a PA11 or PA12 matrix. In another alternative, the processmay start with magnetically isotropic powder, which is preferred becauseit comes with lower assembly costs and more flexibility. In anotheralternative, the process may start with prefabricated compound (Neofer®25/60p) from Magnetfabrik Bonn GmbH, for example.

Further, an exemplary embodiment of the present invention relates to amethod of making a magnetized medical implant. The exemplary methodincludes the steps of providing a substrate and depositing a magnetnano-particle layer onto a surface of the substrate and/or within a newor additional layer onto a substrate or base. The method may includemagnetizing the magnetizable layer by exposing it to a magnetic field,as well as depositing a corrosion resistant layer onto the magnetizablelayer. The method may further include depositing a wear resistant layeronto the corrosion resistant layer. The corrosion and wear resistantlayers may be deposited using a process selected from the groupconsisting of chemical vapor deposition, physical vapor deposition,sputtering, and plating.

An exemplary nano-magnetic prosthetic joint comprises at least onecomponent that includes at least a first plurality of nano-magnetsconfigured to create a magnetic field within, about, and/or surroundingthe joint, the magnetic field directed to influence the articulation andsmooth and sturdy translation of the joint through its ranges of motionin vivo. The components of the prosthetic joint, therefore, may beinfluenced by the magnetic force (a non-mechanical force, for example)while in their mechanical arrangement in vivo. In this way, thereduction of resistance to articulation, and/or the augmentation of thestructural integrity and support, of the articulating junction, viaelectro-magnetism, in vivo reduces the possibility of osteolysis at thebone interface, which in turn may reduce the incidence of prosthesisfailure. In addition, any debris particles that include physiologicalcomponents, such as antibodies or macrophages, for example, will alsoinclude the nano-magnetic particles and may be influenced byinternal/external magnetic field(s).

Further, an exemplary nano-magnetic prosthetic joint may be suitablefor: a hip joint prosthesis, a knee joint prosthesis, a shoulder jointprosthesis, an ankle joint prosthesis, or an elbow joint prosthesis,etc. Although the artificial joint prostheses are described hereinprimarily in reference to humans, in some embodiments the artificialjoint prostheses as described herein will also have applicability inveterinary medicine.

Further, an exemplary nano-magnetic prosthetic joint comprises at leastone component with a bone-facing surface of the artificial jointprosthesis, the bone-facing surface configured to face a bone-prosthesisinterface in vivo. For example, the bone-facing surface of a componentof the artificial joint may include: a region of a shell of a acetabularcomponent of a hip joint prosthesis; a region of a liner of a acetabularcomponent of a hip joint prosthesis; a region of a stem of a femoralcomponent of a hip joint prosthesis; a region of a femoral component ofa knee joint prosthesis; a region of a tibial component of a knee jointprosthesis; a region of a humeral stem of a shoulder joint prosthesis; aregion of a humeral component of a shoulder joint prosthesis; or aregion of a glenoid component to a scapula of a shoulder jointprosthesis.

Further, an exemplary nano-magnetic prosthetic joint comprises at leastone component with a contact surface, wherein the component isfabricated from at least one polymer integrating a plurality of magneticparticles. For example, in some embodiments, the component is fabricatedfrom at least one polymer integrating a plurality of magnetic particlescan include: an acetabular component of a hip joint prosthesis; a headof a femoral component of a hip joint prosthesis; a femoral component ofa knee joint prosthesis; a tibial component of a knee joint prosthesis;a patellar component of a knee joint prosthesis; a humeral component ofa shoulder joint prosthesis; or a glenoid component to a scapula of ashoulder joint prosthesis. In some embodiments, the component isfabricated from a polymer including the plurality of nano-magneticparticles embedded in a polymer matrix. In some embodiments, thecomponent is fabricated from polyethylene including the plurality ofmagnetic particles embedded in a polymer matrix.

In some embodiments, the component is fabricated from at least onemagnetic, polymer nano-composite material. In some embodiments, theplurality of magnetic particles include magnetic nanoparticles, whichare magnetic particles sized between approximately 100.0 nanometers (nm)in diameter and approximately 1.0 nanometer (nm) in diameter. In someembodiments, the component is fabricated from a polymer including aplurality of magnetic nanoparticles at an average density no less than10.0 magnetic nanoparticles per square micron (μm²) of the polymer. Insome embodiments, the component is fabricated from a polymer including aplurality of magnetic nanoparticles at an average density no less than100.0 magnetic nanoparticles per square micron (μm²) of the polymer. Insome embodiments, the plurality of magnetic particles includesferromagnetic particles. In some embodiments, the plurality of magneticparticles includes paramagnetic particles. The polymer integrating aplurality of magnetic particles may include polyethylene magneticparticles.

In some embodiments, the polymer integrating a plurality of magneticparticles may include polyethylene magnetic nanoparticles. The magneticparticles may be integrated into a polymer during fabrication of theartificial joint component. The polymer integrating a plurality ofmagnetic particles may include ultra-high-molecular weight polyethylene(UHMWPE). The polymer integrating a plurality of magnetic particles mayinclude highly cross-linked UHMWPE.

The “contact surface” of an exemplary nano-magnetic prosthetic joint, asused herein, refers to a surface of a component that is expected to comeinto contact with another component of the joint during normalphysiological use of the artificial joint in vivo. For example, acontact surface may include a joint-facing surface of an acetabularliner of a hip joint, a joint-facing surface of a head of a femoralcomponent of a knee joint, or a joint facing surface of a glenoidcomponent to a scapula of a shoulder joint prosthesis. A componentincluding a load-bearing surface is a structural component of theartificial joint during expected physiological use of the joint. As usedherein, a “non-contact surface” of an artificial joint prosthesis refersto a surface of a component of the artificial joint prosthesis that isexpected to not come into contact with the bone and also to not comeinto contact with a surface of another component of the artificial jointprosthesis during normal physiological use of the artificial jointprosthesis in vivo. In some instances, a contact surface of anartificial joint may be a “load bearing surface,” or a surface of ajoint component that is expected to come into contact with anothercomponent and to partially support the mass of the individual userduring normal physiological use of the artificial joint in vivo. Acomponent including a load-bearing surface is a structural component ofthe artificial joint during expected physiological use of the joint invivo.

In some embodiments, a contact surface of an artificial joint componentincludes one or more indentations at the contact surface. Theseindentations can be formed as lines, channels or patterns at the contactsurface. A contact surface of an artificial joint component may include,for example, one or more grooves in the contact surface. Theindentations or grooves in the contact surface are configured to providea space for any limited wear debris from the artificial joint toaccumulate away from a direct contact area of the contact surface.

In some embodiments, the artificial joint components include at leastone component configured to magnetically shield the component includingat least one magnet. The shielding component can, for example, beconfigured to minimize the magnetic field's influence beyond theimmediate joint region.

Some embodiments include at least one fluid deflecting structureattached to a non-contact surface of the artificial joint. One or morefluid deflecting structures can, for example, be configured to operatesynergistically with the magnetic field. Fluid deflecting structures canbe configured, for example, as a flange or cuff-like structure attachedto a non-contact surface of the artificial joint. Fluid deflectingstructures can be configured, for example, as a plurality of ciliatedprojections. The fluid deflecting structures may be configured to divertsynovial fluid flow away from the prosthesis-bone interface duringphysiological activity, and towards a desired location, such as inaccord with the magnetic field(s) for example. The synovial fluiddeflecting structures of the artificial joint prosthesis also may beconfigured to decrease the transient synovial fluid pressure at theprosthesis-bone interface during physiological activities.

The reduction of synovial fluid flow as well as transient pressure atthe bone-prosthesis interface may lead to a reduction of any limiteddebris particles that may enter the prosthesis-bone interface duringphysiological movement. This may decrease the risk of osteolysis relatedto wear debris particles at the prosthesis-bone interface, therebyreducing the risk of prosthesis failure and the need for revisionsurgery with its associated costs and morbidity. In some embodiments,the prosthesis structures can include additional chemical inhibitors ofosteolysis.

Returning to exemplary embodiments of a nano-magnetic prosthetic joint,one embodiment relates to a prosthetic bearing component for use in ajoint replacement. The component may include a first element having afirst magnetic nano-particle layer disposed thereon. There also may be asecond element having a second magnetic nano-particle layer disposedthereon. The second element may be configured to engage the firstelement. The prosthetic bearing component may comprise a corrosionresistant layer covering the surfaces of the first and second elementsabout the first and second magnetized layers. Further, the componentalso may include a wear resistant layer covering the surfaces of thefirst and second elements adjacent the corrosion resistant layer andforming a bearing surface of the prosthetic bearing component.

Further, in an exemplary embodiment of a bearing surface of theprosthetic bearing component, the corrosion resistant layer is composedof a material selected from the group consisting of titanium, niobium,chromium, zirconium, tantalum, gold, silver, titanium nitride, titaniumaluminum nitride, titanium carbonitride, chromium nitride, chromiumcarbonitride, zirconium nitride, and zirconium carbonitride, etc. Thecorrosion resistant layer may be configured as a film with a thicknessof 0.1-50 microns. The exemplary embodiment of a bearing surface alsocomprises a wear resistant layer composed of a material selected fromthe group consisting of chromium oxide, aluminum oxide, chromiumcarbide, zirconium oxide, polyurethane, artificial cartilage, and ultrahigh molecular weight polyethylene. The wear resistant layer also may bea film with a thickness of 50.0-1000.0 microns. The corrosion resistantlayer may be a film with a thickness of 0.1-5.0 microns. It should benoted that there are various options proven at industrial scale forproducing titanium, tantalum, and various other metals and innovativealloy powders for the additive manufacturing market.

Returning to exemplary embodiments of a nano-magnetic prosthetic joint,one embodiment may comprise embedded iron oxide-based magneticnano-particles in ultra-hard, molecular-weight polyethylene. Thenano-particles are embedded without altering the chemical or structuralproperties of the hard plastic. Too many nano-particles weaken theproperties of the plastic. Further, the polyethylene is an incrediblystrong material, more scratch-resistant than carbon steel; however, itsweakness, even in the inventive concept, is that chemical oxidationdegrades the plastic.

As such, the exemplary embodiment takes into consideration and expectsthat each fragment of the polymer formed from wear during physiologicaluse of the joint will include at least one of the magneticnano-particles. The polymer fragments, therefore, are expected to havemagnetic properties as a consequence of the inclusion of the magneticnano-particles within the polymer structure.

It is envisioned that magnetic field may be directed to influence alocation of debris including the magnetic particles in the joint to aposition distinct from the bone-prosthesis interface in vivo. Thefragments, therefore, of the polymer may be influenced by the magneticfield to a location within the joint that is distinct from thebone-prosthesis interface in vivo. The minimization of wear particledebris at the bone-prosthesis interface in vivo may reduce thepossibility of osteolysis at the bone interface, reducing the incidenceof prosthesis failure. In addition, any debris particles that includephysiological components, such as antibodies or macrophages, will alsoinclude the magnetic particles and be influenced by the magnetic field.For example, a macrophage that has engulfed any fragments includingmagnetic particles would be influenced by the magnetic field within thejoint.

Further, the exemplary artificial joint can include a second componentof the artificial joint prosthesis including at least one magnetconfigured to create a magnetic field within the artificial joint, theat least one magnet positioned to form a magnetic field directed toinfluence a location of debris including the magnetic particles in thejoint to a position distinct from the bone-prosthesis interface in vivo,wherein the location is within the indentations or grooves in thecontact surface.

Further, the exemplary artificial joint can be used in conjunction withan external magnetic field. For example, the artificial joint may beused with an external magnetic field to enhance or promote the movementof wear fragments including the magnetic nano-particles to a particularlocation within the joint. For example, an external magnetic field maybe applied periodically with the external magnetic field configured toprovide greater magnetic field strength to the existing field of thejoint. The external field can operate additively or synergistically, forexample, with the internal field of the joint. The artificial joint alsomay be used in conjunction with an external magnetic field to determinethe present, approximate number, concentration, and size of wearfragments including magnetic particles.

Further, and again at a very high level, an exemplary embodiment of thepresent invention provides a prosthetic system comprising a magneticsystem configured to yield a specific pre-determined stray magneticfield of complex form. The stray field may be configured as a specialmagnetic field. In one exemplary embodiment, in order to achieve suchrequirements, the magnetic system comprises magnetic patterns, shapes,and/or bulk geometric structures, programmable magnets, and/orequivalents, manufactured at least in part via software-controlledmagnetization processes. Additive manufacturing of the prosthetic systemmay be involved; however, it is envisioned that similar principles maybe applied without having to create a bonded magnet.

Further, the magnetic system may be designed via computer software,before or during, which adjusts the shape until all requirements for thedesired magnetic profile are met. In one exemplary embodiment involvingadditive manufacturing, once the desired geometric shape and magneticprofile is computed, the additive manufacturing system may use specialtyproduced filament(s) of a magnetic particle held together by a polymerbinding material. The additive manufacturing system may prepare theadditive material(s) for application and may apply it/thempoint-by-point in the desired locations with a variable magneticcompound fraction distribution. This means that saturation magnetizationcan be adjusted during the printing process to obtain the desiredexternal field via, at least in part, a variable magnetic compoundfraction. The result may be a prosthetic system comprising a componentor portion or region or gradient composed of roughly between 70-90%magnetic material and 30-10% substrate in some regions, and also roughlybetween 40-65 vol. % magnetic material in other regions. This results ina customized, made-to-order, on-demand system that is cost- andtime-effective, which can be customized and adjusted before or duringmanufacture.

In another exemplary embodiment, a twin-screw mixing extruder is used tomix magnetic filaments/source material with bio-prosthetic preferredsubstrate material/filaments. The magnetic source material and thesubstrate material are compounded, extruded, and characterized orprepared to be characterized for the printing process. It is envisionedthat the printing process is carried out directly from formless (liquid,powders, etc.) or form-neutral (tape, wire) material, mostly be means ofthermal or chemical processes. No specific tools or methods arerequired; however, fused deposition modeling technology may be employedfor this embodiment. It is envisioned that the magnetic particles may beinitially produced by a melt spinning process (described in greaterdetail herein), wherein ribbons or flakes with a size about 200 micronsis produced (inert gas atomization processes are also envisioned toproduce spherical particulates of approximately 45 microns; otherprocess yield spherical particles having a diameter of approximately50+/−20 microns). Further, it is envisioned that the mixing extruderscan continuously change between materials of different concentrationsand/or compositions, and that a laser diameter measuring system iscompatible to control the diameter tolerances of the filaments.

Further, an exemplary embodiment of the present invention provides aprosthetic system comprising a magnetic system configured to yield aspecific pre-determined stray magnetic field, but which requires asoftware-controlled magnetization process to adjust the orientationand/or polarity of the magnetic system (before or during manufacture).The software-controlled magnetization process enables precision controlover the magnetic field of the final product. The magnetization systemmay comprise an electromagnet, for example, a water-cooled electromagnetpowered by a low-voltage power supply such as a Siemens® NTN 35000-200or equivalent. The magnetization system allows new magnetic designs tobe created on a computer alongside prosthetic engineers and reproducedrapidly, with a precision of well under one millimeter. It is envisionedthat the magnetization system may involve locally magnetizing, oraligning, the magnetic particles if applicable during the solidificationprocess of the surrounding substrate.

In this way, the magnetic system may provide improved attraction forces,repulsion forces, and/or alignment for the prosthetic system, which isimpossible with conventional standard magnet plugs or plates. Forexample, the magnetic system may be engineered to hold certaincomponents of the prosthetic in proper alignment when properlyattached/engaged. The magnetic system also may be engineered with adistinct and separate force curve to also lightly repel aligned orpartially aligned if the components are too close. In the end, themagnetic system may operate at least in part as a polymagnetic springand/or polymagnetic latch and/or equivalent.

In order to accomplish these ends, the magnetization system may apply,at least in part, Barker correlation codes from communications theory.More specifically, when mathematical waves or curves such as sine wavesare in phase, they are additive and reinforcing. When they are out ofphase, they can actually cancel each other out, entirely or in part.Barker correlation codes are unique sequences of + and − in a functionsuch that when certain parameters line up, the two functions resonateswith one another, but when certain parameters do not line up, or areshifted, the resonance between the two functions falls off. Instead ofcurves being in and out of phase by time (communications theory), thepatterns of magnetic north and south poles can be in and out of phase byposition—physically shifting or offsetting the poles past each other.The magnetization system may calculate based on the Barker code behaviorto pattern magnetic north and south poles in the magnetic system. Thisresults in an overall system and method where the final product isspecifically tailored to (1) how tightly the magnetic system/componentsattract and hold one another, (2) how abruptly the attraction/repulsionfalls off as the magnetic system/components areshifted/displaced/pivoted with respect to one another, and/or (3) howlimited or not limited the field strength extends to avoid interferencewith external objects.

Further, an exemplary embodiment of the present invention an exemplaryembodiment of the present invention provides an exemplary embodiment ofa prosthetic joint comprising correlated magnet pairs programmed toattract and/or repel with a prescribed force and engagement distance, orto attract and/or repel at a certain spatial orientation. The correlatedmagnet pairs incorporate correlated patterns of magnets or magneticparticles/granules with alternating polarity, designed to achieve adesired force curve profile. The correlated magnets may be engineered tointeract only with other magnetic structures that have been similarlyengineered to respond, for example, with others that yield a cog-shapedfield. The correlated magnet pairs may be programmed to attract or repelwith a prescribed force and engagement distance, or, to attract or repelat certain spatial orientations. The correlated magnet pairs also may beprogrammed to attract and repel at the same time by varying themultipole structure of the maxels by varying size, location,orientation, and saturation. The maxels may range from 1 mm to 4 mm inone exemplary embodiment.

The Figures and the related description are offered for illustrativepurposes and depict exemplary embodiments of a magnetic joint prostheticin accordance to the solution. As such, the exemplary embodiments shownin the Figures do not illustrate all features and aspects that may beincluded in a given embodiment of the artificial magnetic jointprosthetic in accordance to the solution. For instance, it is envisionedthat the magnetic joint prosthetic according to the solution may bemanufactured into any given joint suitable for the implantation into ahuman living body and/or may be constructed from any combination ofmaterials depending on the intended use of the particular embodiment.The encapsulated magnetic particles/granules of an embodiment may bedispersed into a solution of methyl methacrylate (PMMA),polyethylene(PE) or a biocompatible oxide ceramic, etc. 3D MetalPrinting of Nano-Magnetic Prosthesis

It is envisioned that a technology software platform will be used forthe design of a patient-specific prosthetic implant. An algorithm basedon the patients anthropometrics converts the two dimensional CT scan ofthe joint to a three dimensional (3D) model by mapping the articularsurface of the joint and defining the area of disease and healthy joint.It is envisioned that the software will use this information to designthe implants that will match precisely to the 3D model of the joint. Inthis 3D environment, it is envisioned that the software will recreatethe natural J curve of the joint correcting for any underlying arthriticdeformity such as bone spurs or flattening of the joint. The softwarewill then build either the tibial and femoral implants for the knee orthe acetabular component, femoral head and femoral stem for the hip tomatch the unique size and shape of the joint eliminating pain ordiscomfort.

Further, it is envisioned that a 3D metal printer may be used to createthe nanomagnetic prosthetic by way of additive manufacturing method.Additive manufacturing allows for the fabrication of complex parts thatcannot be manufactured by traditional machines, creating apatient-specific prosthetic joint that is efficient and high performing.This method is the process of creating 3D objects in which layers ofmaterials, in this case powder nanomagnetic particles and otherembodiments thereof, are formed to create the prosthetic joint.

As is understood by one of ordinary skill in the art, there are majorprocesses for metal 3D printing. It is envisioned but not limited to oneof ordinary skill in the art to use either the powder bed fusionprocess, binder jet process, freeform direct laser deposition processand other known processes thereof. Further, it is envisioned that the 3DCT scan may be converted to a virtual image for the purpose of verifyingthat the design is anatomically functional. This validated 3D design maythen be printed in plastic creating an actual 3D part versus a virtualdesign by a common process known to one in ordinary skill of art. It isfurther envisioned that proposed fabrication of the nanomagneticprosthesis by way of using a 3D metal printer, may use nanomagneticpowder and other embodiments thereof. The nanomagnetic powder and otherembodiments thereof, may be spread onto the substrate plate and a powderreservoir of the 3D metal printer.

An exemplary printer has a high-powered watts laser and a blade mostcommonly used, will carry the powder across the substrate plate buildinglayers having thickness ranges of 20.0 to 100.0 μm, or 1.0 to 100.0 μm.Once the powder layer is distributed, the laser may either selectivelymelt or bound the nanomagnetic particles together to form a solid partbuilding layer by layer until the shape of a knee or hip joint, but notlimited to these particular joints to one of ordinary skill in the art,is formed. Once the nanomagnetic joint is printed, it is envisioned thatthe joint may be scanned again to measure the dimensions and validatethat the criteria for the design.

Anthropometrics

It is envisioned that weight may be measured to the nearest 0.1 kg (withthe subject's shoes, socks, and bulky clothing removed), with a singlepair of electronic scales that will calibrate the weight. Height may bemeasured to the nearest 0.1 cm (with shoes and socks removed) using astadiometer. Body mass index (BMI) may be calculated as weigh(kg)/height (m²).

Computerized Tomography (CT Scan)

A computerized tomography (CT) scan combines a series of X-ray imagestaken from different angles and uses computer processing to createcross-sectional images of the bones to provide more detailed informationabout the structure of the bones. It is envisioned that a CT scan may beused to visualize the whole joint of both the healthy knee or hip jointand the diseased knee or hip joint to allow for a customized fit, forexample.

Certain embodiments disclosed will become more apparent from thedrawings and following description.

FIG. 1 is an illustration of an exemplary embodiment of a prior artbasic artificial knee joint structure showing a diseased knee replacedby an artificial joint made of either metal alloys, high grade plasticsor polymers, in which a plastic spacer in placed between the femoral andtibial component. As can be seen, FIG. 1 illustrates a knee jointdamaged by trauma or disease 100A. During a knee arthroplasty procedure,portions of the damaged cartilage and bone is removed from the surfaceof the knee joint and replaced with man-made surface of metal and/orplastic 100B. In the FIG. 1 illustration a femoral component composed ofeither metal alloys, high grade plastics or polymers 100C, a plasticspacer 100D, and tibia component composed of either metal alloys, highgrade plastics or polymers 100E can be seen.

In an exemplary embodiment of a healthy, well aligned knee joint, themechanical axis which is the line extending from the center of the hipjoint to the middle of the ankle joint passes through the middle of theknee. Only when the mechanical axis passes through the center of theknee joint, the stresses on the knee joint surfaces are uniform in allareas of the joint and well balances. In many knee joint diseases, themechanical axis is disturbed and does not pass through the center of thejoint. This disturbance results in the overload of distinct areas of theknee joint leading to their damage. The surgeon must restore themechanical axis of the knee joint during the total replacement surgery.If a total knee prosthesis is not realigned properly the joint willbecome overloaded leading to dislocation, loosen or break down.

FIG. 2 is an illustration of an exemplary embodiment of a prior artbasic artificial hip joint structure showing a diseased hip replaced byan artificial joint made of either metal alloys, high grade plastics orpolymers, in which a plastic spacer in placed between the acetabularcomponent and femoral head. As can be seen, FIG. 2 illustrates, a hipjoint damaged by trauma or disease 200A. During a hip arthroplastyprocedure, portions of the damaged cartilage and bone is removed fromthe surface of the knee joint and replaced with man-made surface ofmetal and/or plastic 200B. In the FIG. 2 illustration, an acetabularcomponent 200C, a femoral head 200D, a femoral stem 200E all composed ofeither metal alloys, high-grade plastics or polymers can be seen.

FIG. 3 is an illustration of an exemplary embodiment of a magneticnano-particle with a magnetic core and a biocompatible coating. Thisfunctional magnetic nanoparticle consists of a number of components; themagnetic core 300A, the protective coating 300B and the biocompatiblesurface coating 300C. Advantageously, it is envisioned that the magneticcore materials 300A will be composed of the preferred embodimentaccording to the solution of either iron oxide, iron alloyed, or rareearth metal alloyed-based materials thereof. It is envisioned that themagnetic core nanomaterial will have a protective coating 300B with apreferred embodiment according to the solution of either naturalpolymers such as carbohydrates and proteins thereof; synthetic organicpolymers such as poly(ethyleneglycol) (PEG), polyvinyl alcohol (PVA) andpoly-L-lactic acid (PLA) thereof; silica and gold. Furthermore, tocontrol the biological response in the material, it is envisioned thatthe biocompatible surface coating 300C will have the preferredembodiment according to the solution of a bio-compatible protein, suchas tropoelastin, collagen, albumin, keratin, fibronectin, actin,mysosin, fibrinogen, thrombin, aprotinin, antithrombin thereof and abio-compatible antimicrobial such as a parylene polymer thereof.

Optionally, the biocompatible surface may be a biocompatible filmdeposited on the surface of the nano-magnetic particle. Optionally, thenano-magnetic particle may have the biocompatible surface coatingapplied by dipping the particle into a solution containingbio-compatible proteins and antimicrobials. Optionally, thenano-magnetic particle may have the biocompatible surface coatingapplied by spraying the biocompatible protein and antimicrobial solutionto allow for a controlled application and uniform coating. The presentsolution is not limited to a particular material onto which a magneticnanoparticle is formed, the underlying material used for thenano-magnetic prosthesis may be chosen according to a variety offactors, such a mechanical stability and ease of function.

FIG. 4 is a perspective view of an exemplary embodiment of a detachednano-magnetic knee replacement in accordance with an exemplaryembodiment to the solution, including components composed of hardenedmagnetic nano-particles that either partially coat or fully coat thejoint. One embodiment for knee joint replacements as shown in FIG. 4A,which includes femoral head component 400 and a tibia head component404. Both femoral head 400 and tibial component 404 components havehardened magnetic nano-particles placed in each component. In thedepicted embodiment of FIG. 4B, hardened magnetic nano-particles arefully embedded on the upper top portion of the femoral head 410. In thedepicted embodiment of FIG. 4C, hardened magnetic nano-particles arepartially embedded on the lower top portion of the femoral head 420 andthe upper top portion of the tibia component 422. In the depictedembodiment of FIG. 4D, hardened magnetic nano-particles are fullyembedded in the femoral head 430 and the tibia component 432.

FIG. 5 is a perspective view of an exemplary embodiment of an attachednano-magnetic prosthesis to its respective knee joint in accordance withan exemplary embodiment to the solution, including components composedof hardened magnetic nano-particles that either partially coat or fullycoat the joint. One embodiment for knee joint replacements is shown inFIG. 5A, which comprises femoral component 500 comprising a femoral headcomponent 502 and a tibia component 504 comprising a tibia headcomponent 506. Both femoral head 500 and tibial component 504 componentshave hardened magnetic nano-particles placed in each component to give amore stable connection when align at a boundary of the predefinedfunctional range of motion. In the depicted embodiment of FIG. 5B,hardened magnetic nano-particles are fully embedded on the upper topportion of the femoral head 510. In the depicted embodiment of FIG. 5C,hardened magnetic nano-particles are partially embedded on the lower topportion of the femoral head 520 and the upper top portion of the tibiacomponent 522. In the depicted embodiment of FIG. 5D, hardened magneticnano-particles are fully embedded in the femoral head 530 and the tibiacomponent 532.

The embedment of the nano-magnetic particles in the anterior andposterior surface areas of the knee joint components are determined inrelation to the anticipated physiological placement of the componentswhen in contact with the condyles in femoral and tibia, for example, andmay be uniquely defined by positional unique anatomical features of thecomponents (e.g., where the components comprise anatomical featuresdesigned to be secured in a single unique anatomical orientation suchas, e.g., the J-shaped curve extending from posterior side of femoral tothe anterior articular surface of the tibia), or by actual designationmarkings provided on the component specifying which areas should bepositioned anteriorly or posteriorly when secured. More particularly,e.g., where a femoral head attached to an essential tibia component isemployed, one section of the surface head of the femur may be marked asthe designated posterior and the tibia surface may be marked as anterior(i.e. the femoral head and tibia having fully embedded nano-magneticparticles therein as oppose to partial), and the surgeon may thenaccordingly correctly position such component based on such marking. Themarkings may be in the form well known to those skilled in the art. Thecomponents may further be designated as medial and lateral condyle,allowing for the further specific whole or partial embedment ofnano-magnetic particles aligned laterally or medially in accordance withfurther specific embodiments.

FIG. 6 a perspective view of an exemplary embodiment of a detachednano-magnetic hip replacement in accordance with an exemplary embodimentto the solution, including components composed of hardened magneticnano-particles that either partially coat or fully coat the joint. Oneembodiment for hip joint replacements is shown in FIG. 6A, whichcomprises femoral component 600 comprising a shaft portion 601 and afemoral head portion 602 having a commonly spherical shaped socketportion. Acetabular component comprises a cup shaped socket portion 612fixed to the pelvis. Socket portion 614 has an inner concave surfacegenerally corresponding to the spherical surface of the femoral headportion. The femoral head 600 and acetabular socket 602, 612 componentshave hardened magnetic nano-particles placed in each component. In thedepicted embodiment of FIG. 6B, hardened magnetic nano-particles arepartially embedded on the upper top portion of the femoral head 620 andthe lower socket portion of the inner concave surface of the acetabularcomponent 622. In the depicted embodiment of FIG. 6C, hardened magneticnano-particles are partial embedded in the top upper portion of femoralhead 630 and the entire socket portion and inner concave surface of theacetabular component 632. In the depicted embodiment of FIG. 6D, theentire acetabular component 640, femoral head 642 and femoral stem 644are composed of hardened magnetic nano-particles.

FIG. 7 is a perspective view of an exemplary embodiment of an attachednano-magnetic prosthesis to its respective hip joint in accordance withan exemplary embodiment to the solution, including components composedof hardened magnetic nano-particles that either partially coat or fullycoat the joint. One embodiment for knee joint replacements as shown inFIG. 7A, femoral component 700 comprises a shaft portion 701 and afemoral head portion 702 having a generally spherical shaped socketportion. Acetabular component comprises a cup shaped socket portion 712fixed to the pelvis. Socket portion 714 has an inner concave surfacegenerally corresponding to the spherical surface of the femoral headportion, whereby the spherical surface of the femoral head portion isrelatively displaceable with respect to the concave surface of theacetabular component over to predefines functional range of motion ofthe femoral head portion when positioned within the acetabularcomponent. The femoral head 700 and acetabular socket 702, 712components have hardened magnetic nano-particles placed in eachcomponent to give a more stable connection when align at a boundary ofthe predefined functional range of motion. In the depicted embodiment ofFIG. 7B, hardened magnetic nano-particles are partially embedded on theupper top portion of the femoral head 720 and the lower socket portionof the inner concave surface of the acetabular component 722. In thedepicted embodiment of FIG. 7C, hardened magnetic nano-particles arepartial embedded in the top upper portion of femoral head 730 and theentire socket portion and inner concave surface of the acetabularcomponent 732. In the depicted embodiment of FIG. 7D, the entireacetabular component 740, femoral head 742 and femoral stem 744 arecomposed of hardened magnetic nano-particles.

The embedment of the nano-magnetic particles in the anterior andposterior surface areas of the hip joint components are determined inrelation to the anticipated physiological placement of the componentswhen secured to the femur and pelvis, and may be uniquely defined bypositional unique anatomical features of the components (e.g., where thecomponents comprise anatomical features designed to be secured in asingle unique anatomical orientation such as, e.g., the curve of thefemoral stem portion having an attached femoral head to uniquely fit theleft or right femur), or by actual designation markings provided on thecomponent specifying which areas should be positioned anteriorly orposteriorly when secured. More particularly, e.g., where an femoral headattached to an essential circumferential symmetric acetabular cupcomponent is employed, one section of the surface head of the femur maybe marked as the designated anterior and the cup surface may be markedas posterior (i.e. the femoral head and acetabular cup having fullyembedded nano-magnetic particles therein as oppose to partial), and thesurgeon may then accordingly correctly position such component based onsuch making. The markings may be in the form well known to those skilledin the art. The components may further be designated as lateral ormedial sides, allowing for the further specific whole or partialembedment of nano-magnetic particles aligned laterally or medially inaccordance with further specific embodiments.

FIG. 8 is a side perspective view of an exemplary embodiment of aprosthetic system comprising a magnetic system configured to yield aspecific pre-determined stray magnetic field of complex form. Further,the magnetic system 800 was engineered via computer software, before andduring manufacture, which adjusts the shape until all requirements forthe desired magnetic profile are met. In this particular embodiment, themagnetic system 800 comprises magnetic patterns, shapes, and/or bulkgeometric structures embedded within the prosthetic material. Once thedesired geometric shape and magnetic profile was computed, the additivemanufacturing system used filament(s) of a magnetic particle heldtogether by a polymer binding material. The additive manufacturingsystem prepared the additive material(s) for application and appliedthem for variable magnetic compound fraction distribution 802, whereinthe saturation magnetization was adjusted during the printing process,or prepared for adjustment, to obtain the desired external field 804.

In particular, a twin-screw mixing extruder was used to mix magneticfilaments/source material with bio-prosthetic preferred substratematerial/filaments. The magnetic source material and the substratematerial also were compounded, extruded, and characterized or preparedto be characterized for the printing process. The result is a magneticsystem 800 in the prosthetic comprising a component or portion or regionor gradient 802 composed of roughly between 70-90% magnetic material and30-10% substrate in some regions, and also roughly between 40-65 vol. %magnetic material in other regions.

Further, as stated above, the prosthetic system may comprise a magneticsystem configured to yield a specific pre-determined stray magneticfield 804, but which requires a software-controlled magnetizationprocess to adjust the orientation and/or polarity of the variablemagnetic compound fraction distribution 802 (before or duringmanufacture). The software-controlled magnetization process enablesprecision control over the magnetic field 804 of the final product andthe areas of high and low gauss.

In this way, the magnetic system 800 may provide improved attractionforces, repulsion forces, and/or alignment for the prosthetic, which areimpossible with conventional standard magnet plugs or plates. Forexample, the magnetic system may be engineered to hold certaincomponents of the prosthetic in proper alignment when properlyattached/engaged. The magnetic system also may be engineered with adistinct and separate force curve to also lightly repel aligned orpartially aligned if the components are too close. In the end, themagnetic system may operate at least in part as a polymagnetic springand/or polymagnetic latch and/or equivalent.

FIG. 9 are perspective views of an exemplary embodiment of a prostheticsystem like that of FIG. 8, but to illustrate the repulsive andattraction force possibly involved in the prosthetic system. FIG. 9A inparticular is a front perspective view of an exemplary embodiment of theprosthetic system 900. FIG. 9B in particular is a side cross-sectionview of an exemplary embodiment of the prosthetic system 900. Similarly,FIG. 10 is a magnified perspective view of an exemplary embodiment of aprosthetic system like that of FIG. 9A, but to illustrate the smoothtransition between strong and weak magnetism. FIG. 10 in particular is afront perspective view of an exemplary embodiment of the prostheticsystem 900 and a portion of its variable magnetic compound fractiondistribution 802.

FIG. 11 is a front perspective view of an exemplary embodiment of aminimized prosthetic system comprising a correlated magnet pair 1100programmed to attract and/or repel with a prescribed force andengagement distance, or to attract and/or repel at a certain spatialorientation. The correlated magnet pair 1100 incorporates correlatedpatterns of magnets or magnetic particles/granules with alternatingpolarity, designed to achieve a desired force curve profile. Thecorrelated magnets 1100 are engineered to interact only with othermagnetic structures that have been similarly engineered to yield acog-shaped field. The correlated magnet pair 1100 are programmed toattract or repel with a prescribed force and engagement distance, and,to attract or repel at certain spatial orientations. The correlatedmagnet pair 1100 also is programmed to attract and repel at the sametime by varying the multipole structure of the maxels by varying size,location, orientation, and saturation.

In particular, the correlated magnet pair 1100 apply, at least in part,Barker correlation codes. The correlated magnet pair 1100 may be basedon the Barker code behavior to pattern magnetic north and south poles inthe magnetic system for a particular desired stray field. In thisparticular embodiment, however, as compared to the embodiment of FIGS.8-10, for example, the correlated magnet pair 1100 are embedded withinthe bone of the articulation joint 1110 to be repaired.

Referring now to FIG. 12, the FIGS. are a flow chart of an exemplaryembodiment of a method of manufacturing the magnetic prosthetic of FIGS.9-10, for example. One of ordinary skill in the art understands that theexemplary method 1200 may be performed by various manufacturing meansthat do not limit the scope of the present disclosure.

More specifically, at block 1210 of FIG. 12A, a desired geometric shapeand magnetic profile for a magnetic system of the prosthetic iscomputed, designed and planned. At block 1212 of FIG. 12A, a magneticsource material and a substrate material for the prosthetic arecompounded and characterized, or prepared to be characterized, for theprinting process. At block 1214 of FIG. 12A, a twin-screw mixingextruder is used to mix magnetic filaments/source material withbio-prosthetic preferred substrate material/filaments or othercompositions with different concentrations and constituent components.At block 1216 of FIG. 12A, the mixing extruder continuously changesbetween materials of different concentrations and/or compositions, and alaser diameter measuring system controls the diameter tolerances. Atblock 1218 of FIG. 12B, the additive material(s) for application areapplied point-by-point in the desired locations with a variable magneticcompound fraction distribution as calculated and prepared at block 1210of FIG. 12A. At block 1220 of FIG. 12B, a software-controlledmagnetization system adjusts the orientation and/or polarity of themagnetic system produced from blocks 1210-1218 (before or duringmanufacture) to enable precision control over the magnetic field of thefinal product. Optionally, at block 1222 of FIG. 12B, the magnetizationsystem may apply, at least in part, Barker correlation code behavior topattern magnetic north and south poles in the magnetic system.

Certain steps in the exemplary method described herein naturally precedeothers for the invention to function as described. However, theinvention is not limited to the order of the steps described if suchorder or sequence does not alter the functionality of the system andmethod of the present disclosure. That is, it is recognized that somesteps may performed before, after, or parallel (substantiallysimultaneously with) other steps without departing from the scope andspirit of the invention. In some instances, certain steps may be omittedor not performed without departing from the invention. Further, wordssuch as “thereafter”, “then”, “next”, etc. are not intended to limit theorder of the steps. These words are simply used to guide the readerthrough the description of the exemplary method.

Systems, devices and methods for a novel magnetic prosthetic have beendescribed using detailed descriptions of embodiments thereof that areprovided by way of example and are not intended to limit the scope ofthe disclosure. The described embodiments comprise different features,not all of which are required in all embodiments of a magneticprosthetic according to the solution. Some embodiments of the solutionutilize only some of the features or possible combinations of thefeatures. Variations of embodiments of the solution that are describedand embodiments of the solution comprising different combinations offeatures noted in the described embodiments will occur to persons of theart.

It will be appreciated by persons skilled in the art that systems,devices and methods for a novel magnetic prosthetic according to thesolution are not limited by what has been particularly shown anddescribed herein above. Rather, the scope of systems, devices andmethods a novel magnetic prosthetic according to the solution is definedby the claims that follow.

The invention claimed is:
 1. An artificial joint prosthesis, comprising:a bone-facing surface configured to face a bone-prosthesis interface invivo; a first component comprising a contact surface, the firstcomponent fabricated, via at least an additive manufacturing method,from at least one polymer including a plurality of magnetic particlesembedded in a first polymer matrix; and a second component fabricated,via at least an additive manufacturing method, from at least one polymerincluding a plurality of magnetic particles embedded in a second polymermatrix; wherein the plurality of magnetic particles embedded in at leastone of the first polymer matrix and the second polymer matrix isdistributed within the surrounding polymer as a variable magneticfraction comprising a variable composition between 70.0% and 90.0%magnetic material and is configured to create a magnetic field about theartificial joint, directed to facilitate articulation of the artificialjoint in vivo.
 2. The artificial joint prosthesis of claim 1, whereinthe plurality of magnetic particles embedded in at least one of thefirst polymer matrix and the second polymer matrix is configured withinthe surrounding polymer as a pattern, shape, bulk geometric structure,or combinations thereof.
 3. The artificial joint prosthesis of claim 1,wherein the plurality of magnetic particles embedded in at least one ofthe first polymer matrix and the second polymer matrix is susceptible toa software-controlled magnetization process to adjust the orientation,or polarity, or combinations thereof.
 4. The artificial joint prosthesisof claim 1, wherein the pluralities of magnetic particles embedded inthe first polymer matrix and the second polymer matrix, respectively,are configured to create a magnetic field about the first component andthe second component, respectively, such the magnetic field about theartificial joint yields a force curve characterized by repulsion, whenthe first component and the second component are at or within a distanceapart, and attraction, when the first component and the second componentare further than the distance apart.
 5. An artificial joint prosthesis,comprising: a bone-facing surface configured to face a bone-prosthesisinterface in vivo; a first component comprising a contact surface, thecontact surface configured as a layer, the layer fabricated, via atleast an additive manufacturing method, from at least one polymerincluding a plurality of magnetic particles embedded in a polymermatrix; and a second component fabricated, via at least an additivemanufacturing method, from at least one polymer including a plurality ofmagnetic particles embedded in a polymer matrix; wherein the embeddedmagnetic particles comprise a component selected from a group consistingof an iron oxide, an iron alloy, and a rare-earth metal alloy-basedmaterial, are encapsulated in a protective coating, and are configuredto create a magnetic field about the artificial joint, directed tofacilitate articulation of the artificial joint in vivo.
 6. Theartificial joint prosthesis of claim 5, wherein the protective coatingcomprises a component selected from a group consisting of naturalpolymers, synthetic organic polymers, silica, gold, and combinationsthereof, with a biocompatible superficial surface.
 7. The artificialjoint prosthesis of claim 6, wherein the biocompatible superficialsurface comprises proteins selected from a group consisting of elastin,collagen, albumin, keratin, fibronectin, silk, silk fibroin, actin,myosin, fibrinogen, thrombin, aprotinin, antithrombin III, andengineered proteins thereof.
 8. The artificial joint prosthesis of claim6, wherein the biocompatible surface comprises an antimicrobial agentselected from the group consisting of triclosan, chlorhexidine,benzalkonium parylene polymer, silver and combinations thereof.